By the summer of 2021, we will likely have more vaccine against COVID-19 in the United States than there are people who want to receive it. But for now, while demand for the vaccine is far higher than the supply, we as a state must fairly and equitably manage the challenge.

Since the start of the COVID-19 vaccination program, decisions about vaccine distribution have been left in the hands of governors across the country. After weeks of thought, consideration, consultation, and watching other states struggle to implement complicated eligibility strategies, Governor Ned Lamont concluded that relying primarily on age will maximize the benefits of the vaccine, and reduce harms from COVID-19 most effectively.

Here is why:

The older you are, the more likely you are to die from COVID-19. In fact, 98% of all deaths in Connecticut from COVID-19 were in those aged 50 and older, with most occurring past age 60. Less than 1% of all deaths have occurred in those younger than 40. While some chronic conditions increase the risk of dying from COVID, those conditions, such as cancer and heart disease, also increase with increasing age.

We considered a strategy based on jobs and underlying health conditions. The Centers for Disease Control and Prevention has published two lists of health conditions that either “increase the risk of severe illness” or “may increase the risk of severe illness” from COVID-19. They also recommended a list of frontline essential workers identified as needing priority. This information was very helpful at the beginning of the process, but as we started to operationalize vaccine distribution, Governor Lamont and his advisors clearly saw the problems with moving in that direction.

Once we began to define the boundaries of the lists, we saw that as many as two-thirds of adults in our state would be eligible in the next phase. There were inconsistencies and lack of definition with both lists. Proving and determining eligibility for these categories would place complicated rules and guidelines on our residents, employers and vaccine provider network.

We saw that a group of over one million people with unclear definitions and complicated verification would slow down the process for everyone, push some of the highest risk to the end of a long line, and make it easier for those with connections and resources to jump to the front.

To give you an idea of the confusion we faced, the CDC lists indicate that Type 2 diabetes “increases risk” but Type 1 diabetes “might increase risk.” Should we then include both lists or just one? Smoking is on the “increases risk” list, and cystic fibrosis and asthma are on the “might increase risk” list. Had we gone with only one list, people who smoke but not those with asthma and cystic fibrosis would have been included. Multiply these dilemmas over and over and you can see that there was little possibility of creating a list of conditions that all could agree was fair and equitable and based on science.

In the frontline worker category, “manufacturing” was listed as a category to be included. This includes everything from food and beverages, to chemicals to kitchen cabinet manufacturing. The U.S. Postal Service was listed as essential, yet couriers like UPS and FedEx were not. UPS and FedEx have been delivering the vaccine to our state but were not defined as essential. And, did it make sense for a 64-year-old with heart disease or cancer to have the same priority as a healthy 25-year-old in a front-line job?

On verification, how could vaccinators determine which doctors’ notes were real and which were not? Would we use the honor system? Create a new process? This would slow down the program, leading to more people receiving the vaccination because of their connections, resources, and access to doctors and to employers — while leaving others behind.

With a clear, easily defined eligibility process, residents of Connecticut just need a birth date; something we all have, can easily verify, and that strongly correlates with risk of dying from COVID-19. Now we can focus on equity and reducing death and illness.

Connecticut vaccine providers are committed to targeting vaccine distribution in our highest-risk zip codes. We are reserving appointment slots, launching mobile vaccine teams, conducting out-bound calls, providing transportation and at-home vaccinations, and doing the kind of grassroots organizing and outreach that is required to make this process equitable. Reaching our hardest-hit communities with effective programs, not checking and verifying and clarifying eligibility, is where we should and will focus our efforts.

Dr. Deidre Gifford is the acting commissioner of the Connecticut Department of Public Health.